The research, published in the journal Nature, says the so-called protocluster or group of galaxies is 12.4 billion light years away — suggesting its light began travelling to Earth when the universe was 1.4 billion years old.

One of the researchers, astrophysicist Scott Chapman of Dalhousie University, says the discovery challenges conventional understanding of how structures form in the universe since it happened so quickly and in a space only about three times the size of the Milky Way.